TEL AVIV — Sirens sent residents in northern Israel running for shelter Wednesday after three rockets were launched from southern Lebanon, drawing rounds of cross-border Israeli ­artillery fire and rare overnight strikes, escalating a ­regional security situation seen as a test for Israel's new government.

The relatively small-scale operation, in which two rockets landed in open fields near the northern Israeli city of Kiryat Shemona and another came down inside Lebanon, was carried out by Palestinian groups along Lebanon’s southern border, according to Israeli media. The munitions sparked blazes in both Lebanon and Israel, where extreme heat and strong winds recently have compounded the risk of wildfires.

The incident unfolded on a day of national mourning in Lebanon to mark one year since a huge explosion obliterated Beirut’s port, a disaster that has come to symbolize the country’s crisis of corruption and negligence.

Israel fired more than 100 shells into Lebanon, according to Israeli media reports. It also carried out its first acknowleged airstrikes over the border in eight years, targeting the sites from where the rockets were fired, the military said early Thursday.

The Palestinian groups have attempted similar cross-border attacks in recent months. They operate in an area tightly controlled by the militant group Hezbollah, which is backed by Iran.

The incident comes days after Israeli, U.S. and British officials blamed Iran for a fatal drone strike against a partly Israeli-operated oil tanker off the coast of Oman in the Arabian Sea. Iranian officials have denied any involvement in the strike.

That attack marked the first major confrontation with Iran for Israeli Prime Minister Naftali Bennett, who took office in June following a 12-year stint by Benjamin Netanyahu, Israel’s longest-
serving prime minister. Netanyahu is suspected of having launched a series of attacks targeting Iran, including explosions at the country’s main uranium-enrichment site and the killing of a prominent nuclear scientist.

Israeli Defense Minister Benny Gantz and Foreign Minister Yair Lapid, who met Wednesday with ambassadors of U.N. Security Council countries, said they provided detailed intelligence information proving that Iran struck the oil tanker last week. They said Saeed Ara Jani, head of the drone section of Iran’s Revolutionary Guard Corps, “is the man personally responsible for the terror attacks in the Gulf of Oman.”

Gantz said Amir Ali Hajizadeh, commander of the Revolutionary Guard’s air force, was behind dozens of attacks in the region involving drones and missiles.

“Iran is responsible for dozens of terror attacks across the Middle East,” Gantz said in the meeting. He further charged that Iran “has violated all of the guidelines set in the [2015 Iran nuclear agreement] and is only around 10 weeks away from acquiring weapons-grade materials necessary for a nuclear weapon.” He added: “It is time for diplomatic, economic and even military deeds — otherwise the attacks will continue.”

Iran denies that it seeks nuclear weapons and says it has breached the deal’s limits on uranium enrichment in response to the Trump administration’s withdrawal from the accord and reimposition of sanctions.

Since last week’s drone attack, Bennett has tried to rally international support against Iran. But he also said that Israel was prepared to “act alone” in defense of its national security.

Netanyahu has repeatedly said that Bennett, whose fragile coalition is made up of eight ideologically disparate parties, is too weak to handle what he called an existential threat posed by Iran.

“The Iranians need to understand that it is impossible to sit placidly in Tehran and ignite the entire Middle East from there. That’s over,” Bennett said Tuesday.

This report has been updated.